WO1998031237A1

WO1998031237A1 - Ice containing food product and method of manufacture thereof

Info

Publication number: WO1998031237A1
Application number: PCT/EP1998/000378
Authority: WO
Inventors: Alan John Gerrard; Vijay Arjun Sawant; Loyd Wix
Original assignee: Unilever Plc; Unilever Nv
Priority date: 1997-01-20
Filing date: 1998-01-13
Publication date: 1998-07-23
Also published as: ZA98413B; EP0855141A1; AU6212798A

Abstract

An ice containing food product having a porous structure comprising interconnected ice particles, which ice particles form a continuous ice network, and a process for the manufacture of such an ice containing food product wherein particles of one or more foodstuffs are dry sintered together by the application of pressure at a temperature below 0 °C, each foodstuff to be dry sintered having a significant ice content such that on the application of pressure the particles bind together to form a continuous ice network.

Description

ICE CONTAINING FOOD PRODUCT AND METHOD OF MANUFACTURE THEREOF

Technical Field of the Invention

The invention relates to an ice containing food product and a process for the preparation of this ice containing food product, in particular the ice containing food product is an ice confection such as ice cream or water ice.

Background to the Invention

There is an increasing need to be able to provide novel ice containing food products. In particular, in the field of ice confections it is desirable to be able to provide products having a novel appearance and/or texture.

It is especially desirable to be able to provide a water ice that has a low calorific content and yet is of a soft texture. Such a water ice has the advantage of being particularly refreshing.

However if a low calorie containing water ice is manufactured in the conventional way a very hard block of ice is achieved which is not acceptable to the consumer.

WO 93/21779 (Unilever) discloses a particulate frozen dessert which retains its free-flowing properties on frozen storage. This document mentions that it is possible to sinter together particles by moistening with a cementing fluid material which is afterwards solidified by lowering the temperature. Such a sintering process may be referred to as a wet sintering process. In such a wet sintering process the cementing fluid material, or binder, has a high sugar content and thus the desired low calorie water ice products cannot be manufactured using a wet sintering process . We have now been able to address all of the above mentioned problems . In particular we are now able to provide a low calorie water ice product which has the required soft texture .

Disclosure of the Invention

Accordingly the invention provides an ice containing food product having a porous structure comprising interconnected ice particles, which ice particles form a continuous ice network.

Furthermore the invention provides a process for the manufacture of an ice containing food product wherein particles of one or more ice containing foodstuffs are dry sintered together by the application of pressure at a temperature below 0°C, each foodstuff to be dry sintered having a significant ice content such that on the application of pressure the particles bind together to form a continuous ice network.

Any food product with a significant ice content can be dry sintered. Preferably the ice containing food product is selected from water ice, ice cream, frozen vegetables, frozen fruit and mixtures thereof. Most preferably the ice containing foodstuff is a water ice. By significant ice content is typically meant an ice content of approximately greater than 75%.

By dry sintering is meant that no binder is used to effect the sintering together of the particles. The particles of one or more ice containing foodstuff are bound together to form a product simply by the application of pressure.

Some of the advantages of dry sintering over wet sintering are as follows; 1) Dry sintering is a much faster and more simple process. In particular there is no need to freeze the product in the mould after the application of the sintering process step, in order to be able to de-mould the product. A dry sintered product can be immediately and readily de- moulded after the application of the dry sintering process step.

2) As mentioned above, dry sintering enables low calorie products to be manufactured.

3) A more stable product is provided via dry sintering compared to wet sintering.

4) High quality products containing C0₂-water clathrate- containing particles may be provided. Products containing C0₂-water clathrate-containing particles are known. However in these products the C0₂-water clathrate-containing particles are in contact with a liquid medium and this destabilises the clathrate. Advantageously particles of

C0₂-water clathrate may be included in the mixture of particles to be dry sintered together. The C0₂-water clathrate-containing particles are thus located in a dry system and are therefore much more stable. EP 201 143 (Unilever) discloses a suitable method of manufacture of the C0₂-water clathrate-containing particles.

The product provided by dry sintering has a novel (brittle, crunchy, friable) texture. The product breaks into its individual particles in the mouth.

The product provided has a porous structure with interconnected ice particles forming a continuous network. Unlike products manufactured using a wet sintering process, dry sintered products do not have a continuous matrix. Wet sintered products have a microstructure whereby a discontinuous ice network is located within a continuous matrix.

The pressure applied during the dry sintering process can be any suitable pressure such that the required level of cohesion is achieved between the individual particles. The minimum possible pressure to achieve cohesion will depend on the ice content of the foodstuff and the particle size. Typically the lowest suitable pressure will be approximately 20kN or above, for a minimum of 1 second.

The higher the pressure used to bind the particles of foodstuff the lower the air content between the individual particles within the final product and therefore the less porous the final structure will be.

The ice particle size and shape used can be any suitable size or shape or mixture of sizes and shapes as required to achieve the desired end product.

Typically a particle size of from 0.1 to 10mm will be suitable, preferably from 1 to 5mm. However a product for example incorporating a larger particle size in combination with smaller particle sizes can also be envisaged. The size of the particle used will influence the final texture achieved. The larger the particle size then the higher the porosity for the pressure used.

Usually the particles will be approximately spherical in shape, however the invention is not restricted to spherical shaped particles and any desired particle shape or mixture of particle shapes may be used.

A variety of interesting textures, flavours and product appearances can be achieved by sintering together particles of identical or different flavours, shapes, foodstuffs, sugar contents and colours . The particle of foodstuff may be achieved by any suitable method. For example a block of frozen water ice may be milled to provide the required particles. Alternatively particles may be provided by adding a liquid dropwise into liquid nitrogen to provide approximately spherical particles .

A non-sintered material may be trapped within the continuous ice network of the sintered particles. This non- sintered material may include for example a liquid, sugar crystals, chocolate/fat pieces, fruit pieces and mixtures thereof .

In a particular embodiment of the invention water ice particles having a low solids content (5 wt% or less soluble solids preferably 1 wt% or less soluble solids) are sintered together to provide a high quality, low calorie product .

An alternative embodiment of the invention may be provided by dry sintering together a mixture of two types of particle, the first type of particle having a significant ice content (for example a water ice), the second type of particle having a significant solid fat content (for example chocolate) such that on the application of pressure at a temperature below 0°C the particles bind together.

Any of the products provided according to the invention may be glazed with, for example, chocolate, fat based solutions or an aqueous solution, by a process such as dipping, enrobing, spraying, prior to packaging and subsequent frozen storage. Examples

Example 1

Water ice particles of from 2 to 5 mm in size having two different formulations as detailed below were prepared either by dropping the water ice solution into liquid nitrogen or by freezing individual water ice solution droplets in various shapes and sizes in a freezer.

Blackcurrant Ice Particles %w/w

Locust Bean Gum (LBG) 0.25

Blackcurrant concentrate 3.00

Sucrose 8.00 Citric Acid (Anhydrous) 0.50

Flavourings 1.00

Colouring 1.00

Sodium Citrate Dihydrate 0.20

Water to 100

Lemon Ice Particles

Sucrose 8.00

Locust Bean Gum 0.25

Citric Acid (Anhydrous) 0.60 Sodium Citrate Dihydrate 0.20

Flavourings 0.10

Lemon Concentrate 3.50

Water to 100

A mixture of particles (1:1 ratio) was sintered together with a force of from 20 to 30kN, for 2 to 5 seconds at -10 to -12°C in a disc shape mould of 75mm diameter and 20mm height .

Once the particles had been sintered together a lemon sauce having the following formulation was introduced into the air space between the ice particles Lemon Sauce %w/w

Sucrose ^" 14.00

Fructose 3.00

Locust Bean Gum 0.10 Lemon Concentrate 6.00

Flavourings 0.10

Sodium Citrate Dihydrate 0.40

Water to 100

The product was then frozen and stored. A juicy and very refreshing product was achieved.

Example 2

A lemon water ice mixture having the following formulation was pasteurised, cooled and then frozen into suitable size blocks for milling into particles of 2 to 5 mm in size.

Lemon Ice Particles %w/w

Fructose 4.500

Aspartame 0.074

LBG 0.250

Citric Acid 0.500

Lemon flavouring 0.400

Colouring 0.020

Water to 100

C0₂-water clathrate blocks prepared according to EP 201 143 were milled into 2 to 5mm size particles. These were then dry blended with the lemon ice particles above in a 85:15 ratio. The blend of the ice particles and C0₂-water clathrate were sintered together with a force of 20 to 30 kN, for 2 to 5 seconds at -5 to -6°C in a disc shape mould of 75mm diameter and 20mm height. Example 3

A very low calorie ice mixture was prepared having the formulation given below

Lemon ice particles %w/w Lemon flavour 0 , . 100 Colouring 0 . . 020 Aspartame 0 . . 225 Citric Acid 0 . . 500 Water to 100

The mixture was pasteurised, cooled and then frozen into suitable size blocks for milling into ice particles of 2 to 3 mm in size.

The particles were then sintered together with a force of from 20 to 30kN, for 2 to 5 seconds at -1 to -2°C in a disc shape mould of 75mm diameter and 20mm height.

Example 4

Water ice particles of from 3 to 5mm in size having two different formulations as detailed below were prepared by dropping the water ice solution into liquid nitrogen.

Low Solids Lemon Ice Particles %w/w

Locust Bean Gum 0.200

Fructose 4.820 Aspartame 0.037

Citric Acid (Anhydrous) 0.700

Lemon Flavour 0.075

Colouring 0.020

Water to 100 High Solids Orange Ice Particles

Sucrose ^" 25.000

Locust Bean Gum 0.200

Citric Acid (Anhydrous) 0.700 Orange Flavour 0.075

Colouring 0.020

Water to 100

A mixture of particles (1:1 ratio) were equilibrated to a temperature of from -15°C to - 20°C before being sintered together with a force of from 20 to 30k , for 2 to 5 seconds at -15 to -20oC in a disc shape mould of 75mm diameter and 20mm height.

Once prepared by sintering, the disc shape was placed into a flexible bag and stored frozen. The contents of the bag can then be kneaded by the consumer prior to consumption to provide an ice confection with play value. By using the combination of high solid and low solid particles, the high solids particles will melt more rapidly on handling the product within the bag, resulting in discrete low solids particles located within a syrup. The product can then be consumed with a spoon or straw.

Comparative Example A

Water ice particles of from 2 to 3mm in size were prepared by suitable size frozen blocks of blackcurrant water ice mix of the following formulation;

Blackcurrant Ice Particles %w/w

Locust Bean Gum 0.25

Blackcurrant Juice (6x concentrate) 0.50 Sucrose 8.00

Citric Acid (Anhydrous) 0.50

Flavouring 0.30

Colouring 0.01

Sodium Citrate 0.20 Water to 100

The particles were wet sintered together with a force of from 25 to 30kN, for 2 to 5 seconds at -10 to -12oc in a disc shape mould of 75mm diameter and 25mm height in the presence of a binder (lemon sauce) (ratio of particles to sauce was approximately 4:1) having the following composition;

Lemon Sauce %w/w Sucrose 30.00

Fructose 10.00

Locust Bean Gum 0.10

Lemon Juice (4x Concentrate) 4.00

Flavouring 0.10 Sodium Citrate 0.40

Water to 100

The product after wet sintering was only loosely held together and the sauce remained sticky. Therefore it was very difficult to demould the product without the product falling apart. The only means to successfully demould the product was to harden the product by freezing prior to demoulding. This freezing process results in a more time consuming and less efficient process compared with dry sintering.

Example 5

The lemon sauce composition of Comparative Example A was formed into a frozen disc of approximately 60mm in diameter and 2-3mm in thickness. Essentially a sandwich-like structure was then prepared in a mould of 75mm diameter and 25mm depth with a layer of approximately 12mm in height of blackcurrant ice particles (prepared as in Comparative Example A) placed on the bottom of the mould, followed by the lemon sauce disc and topped with a second layer of approximately 12mm height of the blackcurrant ice particles. The ratio of frozen lemon sauce (as a single disc) to blackcurrant ice particles was 1:4 (as in Comparative Example A) .

The sandwich-like structure was the dry sintered with a force of from 25 to 30k , for 2 to 5 seconds at -10 to -12oC

The product after dry sintering was sufficiently bound together such that it could be readily de-moulded and stored frozen.

Claims

1. An ice containing food product having a porous structure comprising interconnected ice particles, which ice particles form a continuous ice network.

2. An ice containing food product according to claim 1 wherein the food product comprises a foodstuff selected from water ice, ice cream and mixtures thereof.

3. An ice containing food product according to any preceding claim wherein the food product comprises a water ice .

4. An ice containing food product according to claim 3 wherein the water ice has a soluble solids content of less than 5 wt% .

5. An ice containing food product according to claim 3 wherein the water ice has a soluble solids content of less than 1 wt% .

6. An ice containing food product according to any preceding claim wherein the food product comprises non- sintered material trapped within the continuous ice network.

7. An ice containing product according to any preceding claim wherein at least some of the interconnected ice particles are C0₂-water clathrate-containing particles.

8. A process for the manufacture of an ice containing food product wherein particles of one or more ice containing foodstuffs are dry sintered together by the application of pressure at a temperature below 0°C, each foodstuff to be dry sintered having a significant ice content such that on the application of pressure the particles bind together to form a continuous ice network.

9. A process according to claim 8 wherein the pressure applied is approximately 20kN or above.

10. A process according to claim 8 or 9 wherein the foodstuff is selected from water ice, ice cream and mixtures thereof.

11. A process according to claim 10 wherein the foodstuff is a water ice.

12. A process according to claim 11 wherein the water ice has a soluble solids content of less than 5 wt% .

13. A process according to claim 12 wherein the water ice has a soluble solids content of less than 1 wt% .

14. A process for the manufacture of an ice-containing food product wherein particles of two types of foodstuffs are dry sintered together by the application of pressure at a temperature below 0°C, the first foodstuff to be dry sintered having a significant ice content and the second foodstuff to be dry sintered having a significant solid fat content such that on the application of pressure the particles bind together.